Although dogs are famous for their sense of smell, but for some dogs, there good eyesight helps them the most. Dogs are generally nocturnal and hence their night vision is much superior to humans. These is because the cone to rod ratio. The rods aid in night vision while cones aid in day vision. The cone to rod ratio is much smaller in dogs than in humans.

Dogs with the "best" eyesight are probably the so-called "sight hounds". These are dogs which hunt animals by sight - and they can be recognized from their relatively close set eyes at the front of their heads. Examples of such dogs are greyhounds, borzois, Afghans, whippets, deerhounds, and wolfhounds. These breeds also have long legs and streamlined bodies for faster speeds while running and catching prey.

Sight hounds were bred and raised to help the hunters with their excellent eyesight. Instead of finding prey by scent, these lean hunters spot their prey from a great distance; other breeds noted for their eyesight are the Tibetan Terriers.